Y2O3—ZrO2 erosion resistant material for chamber components in plasma environments

ABSTRACT

A method of manufacturing a chamber component for a processing chamber comprises forming a green body using a Y 2 O 3 —ZrO 2  powder consisting essentially of 55-65 mol % Y 2 O 3  and 35-45 mol % ZrO 2 ; and sintering the green body to produce a sintered ceramic body consisting essentially of one or more phase of Y 2 O 3 —ZrO 2 , the sintered ceramic body consisting essentially of 55-65 mol % Y 2 O 3  and 35-45 mol % ZrO 2 .

RELATED APPLICATIONS

This patent application is a continuation of U.S. application Ser. No.16/279,247, filed Feb. 19, 2019, which claims the benefit under 35U.S.C. § 119(e) of U.S. Provisional Application No. 62/639,941, filedMar. 7, 2018, both of which are incorporated by reference herein.

TECHNICAL FIELD

Embodiments of the present disclosure relate, in general, to an erosionresistant ceramic material composed of Y₂O₃ and ZrO₂, and in particularto chamber components manufactured from such an erosion resistantceramic material.

BACKGROUND

In the semiconductor industry, devices are fabricated by a number ofmanufacturing processes producing structures of an ever-decreasing size.Some manufacturing processes such as plasma etch and plasma cleanprocesses expose a substrate to a high-speed stream of plasma to etch orclean the substrate. The plasma may be highly corrosive, and may corrodeprocessing chambers and other surfaces that are exposed to the plasma.

SUMMARY

In one embodiment, a chamber component for a processing chamber (e.g.,for a semiconductor processing chamber) comprises a ceramic bodyconsisting of a sintered ceramic material consisting essentially ofY₂O₃—ZrO₂, wherein the ceramic material consists essentially of 55-65mol % Y₂O₃ and 35-45 mol % ZrO₂.

In one embodiment, a chamber component for a processing chambercomprises a body and a ceramic coating on the body. The body comprisesat least one of a sintered ceramic material or a metal. The ceramiccoating consists essentially of one or more phase of Y₂O₃—ZrO₂, whereinthe ceramic coating consists essentially of 55-65 mol % Y₂O₃ and 35-45mol % ZrO₂.

In one embodiment, a method of manufacturing a chamber component for aprocessing chamber may be performed. The method includes mixing a Y₂O₃powder with a ZrO₂ powder to form a Y₂O₃—ZrO₂ powder consistingessentially of 55-65 mol % Y₂O₃ and 35-45 mol % ZrO₂. The method furtherincludes performing cold isostatic pressing using the Y₂O₃—ZrO₂ powderto form a green body. The method further includes forming the green bodyinto an approximate shape of the chamber component. The method furtherincludes performing a first heat treatment on the green body to burn offan organic binder in the green body. The method further includessubsequently performing a second heat treatment on the green body at atemperature of about 1750-1900° C. to sinter the green body and producea sintered ceramic body consisting essentially of one or more phase ofY₂O₃—ZrO₂, wherein the sintered ceramic body consists essentially of55-65 mol % Y₂O₃ and 35-45 mol % ZrO₂. The method further includesmachining the sintered ceramic body. The method further includesperforming a purification process on the sintered ceramic body to removetrace metals from the sintered ceramic body.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is illustrated by way of example, and not by wayof limitation, in the figures of the accompanying drawings in which likereferences indicate similar elements. It should be noted that differentreferences to “an” or “one” embodiment in this disclosure are notnecessarily to the same embodiment, and such references mean at leastone.

FIG. 1 depicts a sectional view of one embodiment of a processingchamber.

FIG. 2 depicts one embodiment of an electrostatic chuck assembly.

FIGS. 3A-B illustrate a heater substrate assembly in accordance withembodiments.

FIGS. 4A-B illustrate a top view and bottom view of a process kit ring,respectively, in accordance with embodiments.

FIGS. 5A-B illustrate a top view and bottom view of a lid for aprocessing chamber, respectively, in accordance with embodiments.

FIGS. 6A-B illustrate a top view and bottom view of a nozzle for aprocessing chamber, respectively, in accordance with embodiments.

FIGS. 7A-B illustrate a top view and bottom view of a GDP for aprocessing chamber, respectively, in accordance with embodiments.

FIG. 8 is a flow chart showing a process for manufacturing a solidsintered ceramic article, in accordance with one embodiment of thepresent disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the present disclosure provide various chamber componentsfor a processing chamber that are composed of Y₂O₃—ZrO₂ that includes55-65 mol % Y₂O₃ and 35-45 mol % ZrO₂. The chamber components may be orinclude solid sintered ceramic bodies composed of the Y₂O₃—ZrO₂ thatincludes 55-65 mol % Y₂O₃ and 35-45 mol % ZrO₂. Examples of chambercomponents that may benefit from use of the disclosed solid sinteredceramic bodies include nozzles, gas delivery plates, chamber doors,rings, lids, electrostatic chucks, heater substrate supports, and so on.Use of the Y₂O₃—ZrO₂ that includes 55-65 mol % Y₂O₃ and 35-45 mol % ZrO₂to form the chamber components provides advantages over chambercomponents composed of other ceramic materials, including advantagesover chamber components composed of approximately 70% Y₂O₃ andapproximately 30 mol % ZrO₂ in some applications. Such advantagesinclude increased hardness, increased tensile strength and/or increasedwear resistance.

The term “heat treating” is used herein to mean applying an elevatedtemperature to a ceramic article, such as by a furnace. “Plasmaresistant material” refers to a material that is resistant to erosionand corrosion due to exposure to plasma processing conditions. Theplasma processing conditions include a plasma generated fromhalogen-containing gases, such as C₂F₆, SF₆, SiCl₄, HBR, NF₃, CF₄, CHF₃,CH₂F₃, F, NF₃, Cl₂, CCl₄, BCl₃ and SiF₄, among others, and other gasessuch as O₂, or N₂O. he resistance of the material to plasma is measuredthrough “etch rate” (ER), which may have units of Angstrom/min (Å/min),throughout the duration of the coated components' operation and exposureto plasma. Plasma resistance may also be measured through an erosionrate having the units of nanometer/radio frequency hour (nm/RFHr), whereone RFHr represents one hour of processing in plasma processingconditions. Measurements may be taken after different processing times.For example, measurements may be taken before processing, after 50processing hours, after 150 processing hours, after 200 processinghours, and so on. An erosion rate lower than about 100 nm/RFHr istypical for a plasma resistant coating material. A single plasmaresistant material may have multiple different plasma resistance orerosion rate values. For example, a plasma resistant material may have afirst plasma resistance or erosion rate associated with a first type ofplasma and a second plasma resistance or erosion rate associated with asecond type of plasma.

When the terms “about” and “approximately” are used herein, these areintended to mean that the nominal value presented is precise within±10%. Nominal value may also be precise to within +/−2% in embodiments.Some embodiments are described herein with reference to chambercomponents and other articles installed in plasma etchers forsemiconductor manufacturing. However, it should be understood that suchplasma etchers may also be used to manufacture micro-electro-mechanicalsystems (MEMS)) devices. Additionally, the articles described herein maybe other structures that are exposed to plasma or other corrosiveenvironments. Articles discussed herein may be chamber components forprocessing chambers such as semiconductor processing chambers.

Embodiments are discussed herein with reference to chamber componentsthat are formed of bulk sintered ceramic bodies and properties areprovided for such bulk sintered ceramic bodies. However, it should benoted that in some embodiments chamber components may be composed ofdifferent metals and/or ceramics than the described ceramic materialconsisting of one or more phase of Y₂O₃—ZrO₂ and may have a coating thatconsists of the ceramic material consisting of Y₂O₃—ZrO₂ with 55-65 mol% Y₂O₃ and 35-45 mol % ZrO₂. The coating may be formed via a sol-gelcoating technique, a thermal spray coating technique such as plasmaspraying, an ion assisted deposition (IAD) technique, a physical vapordeposition (PVD) technique, a chemical vapor deposition (CVD) techniqueand/or an atomic layer deposition (ALD) technique. Accordingly, thechamber components discussed herein as being solid ceramic articlescomposed of Y₂O₃—ZrO₂ may alternatively be Al₂O₃, AlN, Y₂O₃, or othermaterials that are coated by a coating of the ceramic material composedof Y₂O₃—ZrO₂. Coating properties may be similar to bulk sintered ceramicproperties for the ceramic material consisting of one or more phase ofY₂O₃—ZrO₂ for coatings formed via IAD, PVD, CVD and/or ALD.

FIG. 1 is a sectional view of a processing chamber 100 (e.g., asemiconductor processing chamber) having one or more chamber componentsthat include a plasma resistant ceramic material that consistsessentially of one or more phase of Y₂O₃—ZrO₂, wherein the ceramicmaterial consists essentially of 55-65 mol % Y₂O₃ and 35-45 mol % ZrO₂in accordance with embodiments of the present disclosure. In a furtherembodiment, the ceramic material consists essentially of 56-65 mol %Y₂O₃ and 35-44 mol % ZrO₂. In a further embodiment, the ceramic materialconsists essentially of 57-65 mol % Y₂O₃ and 35-43 mol % ZrO₂. In afurther embodiment, the ceramic material consists essentially of 58-65mol % Y₂O₃ and 35-42 mol % ZrO₂. In a further embodiment, the ceramicmaterial consists essentially of 59-65 mol % Y₂O₃ and 35-41 mol % ZrO₂.In a further embodiment, the ceramic material consists essentially of60-65 mol % Y₂O₃ and 35-40 mol % ZrO₂. In a further embodiment, theceramic material consists essentially of 55-64 mol % Y₂O₃ and 36-45 mol% ZrO₂. In a further embodiment, the ceramic material consistsessentially of 55-63 mol % Y₂O₃ and 37-45 mol % ZrO₂. In a furtherembodiment, the ceramic material consists essentially of 55-62 mol %Y₂O₃ and 38-45 mol % ZrO₂. In a further embodiment, the ceramic materialconsists essentially of 55-61 mol % Y₂O₃ and 39-45 mol % ZrO₂. In afurther embodiment, the ceramic material consists essentially of 55-60mol % Y₂O₃ and 40-45 mol % ZrO₂. In a further embodiment, the ceramicmaterial consists essentially of 56-64 mol % Y₂O₃ and 36-44 mol % ZrO₂.In a further embodiment, the ceramic material consists essentially of57-63 mol % Y₂O₃ and 37-43 mol % ZrO₂. In a further embodiment, theceramic material consists essentially of 58-62 mol % Y₂O₃ and 36-42 mol% ZrO₂. In a further embodiment, the ceramic material consistsessentially of 59-61 mol % Y₂O₃ and 39-41 mol % ZrO₂. In a furtherembodiment, the ceramic material consists essentially of about 60 mol %Y₂O₃ and about 40 mol % ZrO₂. The sintered ceramic body composed of theceramic material of Y₂O₃—ZrO₂ may have a porosity of about 0.1%, wherethe porosity is the pore-volume fraction.

The processing chamber 100 may be used for processes in which acorrosive plasma environment is provided. For example, the processingchamber 100 may be a chamber for a plasma etch reactor (also known as aplasma etcher), a plasma cleaner, and so forth. Examples of chambercomponents that may include or be formed of the ceramic materialconsisting essentially of Y₂O₃—ZrO₂ are a lid 132, a nozzle 152, achamber door 150, a puck 153 of an electrostatic chuck (ESC) 148, a ring(e.g., a process kit ring or single ring) 134, a gas distribution plate(not shown), a heater substrate support (not shown), and so on. Each ofthese chamber components may benefit from use of the ceramic materialthat consists essentially of Y₂O₃—ZrO₂ for one or more reasons. Forexample, a ceramic material of Y₂O₃—ZrO₂ that comprises 55-60 mol % Y₂O₃and 40-45 mol % ZrO₂, 56-64 mol % Y₂O₃ and 36-44 mol % ZrO₂, 57-63 mol %Y₂O₃ and 37-43 mol % ZrO₂, 58-62 mol % Y₂O₃ and 36-42 mol % ZrO₂, 59-61mol % Y₂O₃ and 39-41 mol % ZrO₂, or about 60 mol % Y₂O₃ and about 40 mol% ZrO₂ may have an optimal or close to optimal combination of hardness,erosion resistance, dielectric breakdown resistance, and/or tensilestrength as compared to other ceramic materials (including Y₂O₃—ZrO₂that comprises greater than 65 mol % Y₂O₃ and less than 35 mol % ZrO₂,as well as Y₂O₃—ZrO₂ that comprises less than 55 mol % Y₂O₃ and greaterthan 45 mol % ZrO₂).

Table 1 below provides properties of various bulk sintered ceramicmaterials that include mixtures of Y₂O₃ and ZrO₂ at variousconcentrations. In the table, sample A includes 100 mol % Y₂O₃, sample Bincludes 73.2 mol % Y₂O₃ and 26.8 mol % ZrO₂, sample C includes 64.5 mol% Y₂O₃ and 35.5 mol % ZrO₂, sample D includes 60.3 mol % Y₂O₃ and 39.7mol % ZrO₂, and sample E includes 57.7 mol % Y₂O₃ and 42.3 mol % ZrO₂.As shown, optimal properties for some applications are achieved using60.3 mol % Y₂O₃ and 39.7 mol % ZrO₂. For example, the ceramic materialconsisting essentially of 60.3 mol % Y₂O₃ and 39.7 mol % ZrO₂ exhibitsthe highest average flexural strength, the highest Viker hardness andthe highest fracture toughness of the tested compositions, while alsoexhibiting high modulus of elasticity, density, dielectric breakdownresistance of about 500-600 V/mil and plasma erosion resistance. Similardesirable properties are also achieved using 59-61 mol % Y₂O₃ and 39-41mol % ZrO₂, 58-62 mol % Y₂O₃ and 36-42 mol % ZrO₂, 57-63 mol % Y₂O₃ and37-43 mol % ZrO₂, and so on, with the combination of properties of theceramic material becoming less desirable for the applications thefurther the ceramic material deviates from 60.3 mol % Y₂O₃ and 39.7 mol% ZrO₂. The thermal shock resistivity coefficient (R′) is computed usingthe following formula:

$R^{\prime} = \frac{\begin{matrix}{{Thermal}{conductivity} \times {average}{flexural}{strength} \times} \\\left( {1 - {{Poisson}^{\prime}s{ratio}}} \right)\end{matrix}}{\begin{matrix}{{Modulus}{of}{elasticity} \times} \\{{Thermal}{expansion}{coefficient}}\end{matrix}}$

TABLE 1 Properties of Sintered Ceramic Articles Property Units A B C D EY₂O₃ mol % 100 73.2 64.5 60.3 57.7 ZrO₂ mol % 0 26.8 35.5 39.7 42.3 Avg.Flexural Strength MPa 110 124.6 139.4 150 140 Modulus of Elasticity GPa170 190 196 195 Viker 5 Kgf Hardness GPa 6 9.4 9.1 9.4 Poisson’s Ratio v0.304 0.294 0.293 Fracture Toughness MPa · m^(1/2) 1.2 1.2 1.2 1.3Thermal Expansion Coefficient x10⁻⁶/K 8.2 9.1 9.4 9.5 9.6 (at 20-900°C.) Thermal Conductivity (at 20° C.) W/mK 14 4.6 4.1 3.7 3.5 VolumetricResistivity (at 20° C.) Ohm · cm xE¹⁶ Dielectric Constant (13.56 MHz) —12.5 Tan δ — <0.001 Density g/cm³ 4.92 5.1 5.22 5.25 5.26 Avg. GrainSize μm 25 Thermal Shock Resistivity — 0.751 0.234 0.219 0.241Coefficient (R’)

In one embodiment, the processing chamber 100 includes a chamber body102 and a lid 132 that enclose an interior volume 106. The lid 132 mayinclude a through hole at approximately a center of the lid 132 thatreceives a nozzle 152. The chamber body 102 may be fabricated fromaluminum, stainless steel or other suitable material. The chamber body102 generally includes sidewalls 108 and a bottom 110.

An outer liner 116 may be disposed adjacent the sidewalls 108 to protectthe chamber body 102. The outer liner 116 may be a halogen-containinggas resist material such as Al₂O₃ or Y₂O₃.

An exhaust port 126 may be defined in the chamber body 102, and maycouple the interior volume 106 to a pump system 128. The pump system 128may include one or more pumps and throttle valves utilized to evacuateand regulate the pressure of the interior volume 106 of the processingchamber 100.

The lid 132 may be supported on the sidewalls 108 of the chamber body102 and/or on a top portion of the chamber body. The lid 132 may providea seal for the processing chamber 100. The lid 132 may be opened toallow access to the interior volume 106 of the processing chamber 100 insome embodiments. A gas panel 158 may be coupled to the processingchamber 100 to provide process and/or cleaning gases to the interiorvolume 106 through gas delivery holes in the nozzle 152. Examples ofprocessing gases that may be used to process substrates in theprocessing chamber 100 include halogen-containing gases, such as C₂F₆,SF₆, SiCl₄, HBr, NF₃, CF₄, CHF₃, CH₂F₃, F, Cl₂, CCl₄, BCl₃ and SiF₄,among others, and other gases such as O₂, or N₂O. Examples of carriergases include N₂, He, Ar, and other gases inert to process gases (e.g.,non-reactive gases).

A substrate support assembly such as an electrostatic chuck 148 or aheater substrate support (not shown) is disposed in the interior volume106 of the processing chamber 100 below the lid 132 and nozzle 152. Theelectrostatic chuck 148 holds a substrate 144 (e.g., a semiconductorwafer) during processing. The electrostatic chuck 148 may secure thesubstrate 144 during processing, and may include an electrostatic puck153 bonded to a thermally conductive (e.g., metal) base 154 (alsoreferred to as a thermally conductive plate) and/or one or moreadditional components. The thermally conductive base 154 may be composedof Al. In embodiments, an outer wall of the thermally conductive base154 includes an anodization layer 156 (e.g., an Al₂O₃ anodizationlayer). A ring 134 such as a process kit ring may be disposed on theelectrostatic chuck at an outer perimeter of the electrostatic puck 153in embodiments.

The chamber body 102 may include a cavity in a sidewall of the chamberbody 102. The cavity may be covered by a chamber door 150 inembodiments. The interior body 106 may be filled with plasma duringprocessing and/or cleaning. The cavity may cause a non-uniformity in aradio frequency (RF) field that is produced in the chamber body 102 toaccelerate the plasma. The non-uniformity can cause arcing and anincrease in plasma intensity at the cavity. The chamber door 150 may becomposed of the ceramic material consisting essentially of Y₂O₃—ZrO₂with 55-65 mol5 Y₂O₃ and 35-45 mol % ZrO₂, which provides a highresistance to the plasma in the interior volume 106 and also has a highdielectric breakdown resistance. The high dielectric breakdownresistance may eliminate or reduce any non-uniformity in the RF field,and may eliminate and/or suppress arcing. The ceramic materialconsisting essentially of Y₂O₃—ZrO₂ with 55-65 mol5 Y₂O₃ and 35-45 mol %ZrO₂ also has a high flexural strength, which mitigates or eliminatesbreakage of the chamber door 150. The ceramic material consistingessentially of Y₂O₃—ZrO₂ with 55-65 mol5 Y₂O₃ and 35-45 mol % ZrO₂ alsohas a high hardness, which reduces wear on the chamber door 150. In oneembodiment, the chamber door 150 is a curved flip up door that includesa metal component attached to a ceramic body, where the metal componentincludes and/or is attached to a hinge mechanism. In one embodiment, thechamber door has a thickness of about 0.5-1.5 inches, a first dimension(e.g., length) of about 3-6 inches (e.g., about 4-5 inches) and a seconddimension (e.g., a height) of about 8-16 inches (e.g., about 10-14inches).

FIG. 2 depicts an exploded view of one embodiment of the electrostaticchuck 148. The electrostatic chuck 148 includes the electrostatic puck153 bonded to the thermally conductive base 154. The electrostatic puck153 has a disc-like shape having an annular periphery that maysubstantially match the shape and size of the substrate 144 positionedthereon. The electrostatic puck 153 may include one or more embeddedheating elements and/or one or more embedded chucking electrodes. Theheating elements may be configured to heat supported substrates totemperatures of up to about 350° C. in some embodiments. Theelectrostatic puck 153 may additionally include mesas on a surface ofthe electrostatic puck 153 and one or more gas delivery holes fordelivering a heat conducting gas (e.g., He) between a surface of theelectrostatic puck and a backside of a supported substrate.

In one embodiment, the electrostatic puck 166 may be a sintered ceramicbody fabricated by the ceramic material consisting essentially ofY₂O₃—ZrO₂. The electrostatic puck 166 may have a thickness of 0.04-0.25and a diameter of 7.85-12.90 in some embodiments. In one embodiment, theelectrostatic puck 153 includes a first ceramic body formed of theceramic material consisting essentially of Y₂O₃—ZrO₂ with 55-65 mol5Y₂O₃ and 35-45 mol % ZrO₂ bonded to a second ceramic body consistingessentially of AlN or Al₂O₃. Use of the ceramic material consistingessentially of Y₂O₃—ZrO₂ with 55-65 mol5 Y₂O₃ and 35-45 mol % ZrO₂(e.g., with about 60 mol % Y₂O₃ and about 40 mol % ZrO₂ provides anoptimal or near optimal combination of dielectric breakdown resistance,plasma erosion resistance and hardness for the electrostatic puck 153.The dielectric breakdown resistance and resistivity can be usefulproperties of the electrostatic puck 153 for both Coulombic andJohnsen-Rahbek (JR) electrostatic chucks. Additionally, the erosionresistance should be high to minimize particle contamination andmaximize the life of the ESC 148. Moreover, the electrostatic puck 153makes physical contact with many substrates during use, which causeswear on the electrostatic puck 153. The high hardness of 9.4 GPa resistswear (e.g., due to relative motion because of coefficient of thermalexpansion mismatch between the supported substrate & the electrostaticpuck 153) during processing of the substrate or wafer. The high hardnessof the ceramic material consisting essentially of Y₂O₃—ZrO₂ with about55-65 mol % Y₂O₃ and about 35-45 mol % ZrO₂ minimizes such wear.

The thermally conductive base 154 attached below the electrostatic puck153 may have a disc-like body. The thermally conductive base 154 may befabricated by a material having thermal properties substantiallymatching that of the overlying electrostatic puck 153 in someembodiments. In one embodiment, the thermally conductive base 154 may befabricated by a metal, such as aluminum or stainless steel or othersuitable materials. Alternatively, the thermally conductive base 154 maybe fabricated by a composite of ceramic and metal material providinggood strength and durability as well as heat transfer properties. Thecomposite material may have a thermal expansion coefficient that issubstantially matched to the overlying electrostatic puck 153 to reducethermal expansion mismatch in some embodiments.

The thermally conductive base 154 may be bonded to the electrostaticpuck 153 by a silicone bond in embodiments. In some embodiments, theelectrostatic puck 153 is formed from a first ceramic body of AlN orAl₂O₃. AlN may be used for Johnson-Rahbek electrostatic chucks and A₂O₃may be used for coulumbic electrostatic chucks. The first ceramic bodymay include one or more chucking electrodes and/or one or more heatingelectrodes embedded therein. A second ceramic body (e.g., a thin wafer)formed from Y₂O₃—ZrO₂ with about 55-65 mol % Y₂O₃ and about 35-45 mol %ZrO₂ may be bonded to the first ceramic body by a diffusion bond. Thediffusion bonding may be performed using a temperature of about 120-130°C. and a pressure of up to about 300 pounds per square inch (PSI).

For the diffusion bond between the first ceramic body (of AlN or Al₂O₃)and the second ceramic body (formed from Y₂O₃—ZrO₂ with about 55-65 mol% Y₂O₃ and about 35-45 mol % ZrO₂), an interface layer may be formedbetween the first ceramic body and the second ceramic body. Theinterface layer may be composed of Y, Zr, Al and O.

FIGS. 3A-B illustrate a heater assembly 305 in accordance withembodiments. The heater assembly 305 may be used as an alternativesubstrate support assembly to the ESC 148 in some embodiments. Theheater assembly 305 includes a flat ceramic heater plate 310 that hasone or more embedded heating elements (not shown). The ceramic heaterplate 310 may have a thickness of 0.3-0.9 inches and a diameter of7.9-14.8 inches in some embodiments. The ceramic heater plate 310 mayinclude one or more mesas on an upper surface of the ceramic heaterplate 310 in embodiments. The ceramic heater plate 310 may support asubstrate during processing, and may be configured to heat the substrateto temperatures of up to about 650° C.

The ceramic heater plate 310 may be bonded to a funnel shaped body 320that has a larger inner diameter and outer diameter at a top of thefunnel shaped body 320 than at a bottom of the funnel shaped body 320.The bond between the ceramic heater plate 310 and the funnel shaped body320 may be created by diffusion bonding at a temperature of over 1000°C. (e.g., up to 1800° C.) and a pressure of up to about 800 PSI (e.g.,300-800 PSI) in embodiments. The funnel shaped body 320 may be composedof AlN in embodiments, and may be hollow to minimize heat transferbetween the ceramic heater plate 310 and other components of a chambercontaining the ceramic heater plate 310. The AlN funnel shaped body 320may include one or more dopants to control thermal conductivity.Examples of such dopants include samarium, yttrium and magnesium.

For the diffusion bond between the ceramic heater plate 310 and thefunnel shaped body 320, an interface layer may be formed between theceramic heater plate 310 and the funnel shaped body. The interface layermay be composed of Y, Zr, Al and O.

In some embodiments, the ceramic heater plate 310 is coupled to anadditional ceramic heater plate 315. The additional ceramic heater plate315 may be composed of AlN. In some embodiments, the ceramic heaterplate 310 does not include heating elements, and the heating elementsare instead included in the additional ceramic heater plate 315. Theceramic heater plate 310 may be coupled to the additional ceramic heaterplate 315 by a diffusion bond or by bolts, for example.

The diffusion bond may be created using diffusion bonding at atemperature of over 1000° C. (e.g., up to 1800° C.) and a pressure of upto about 800 PSI (e.g., 300-800 PSI) in embodiments. The additionalceramic heater plate 315 may be bonded to the funnel shaped body 320that has a larger inner diameter and outer diameter at a top of thefunnel shaped body 320 than at a bottom of the funnel shaped body 320.The bond between the additional ceramic heater plate 315 and the funnelshaped body 320 may be created by diffusion bonding at a temperature ofover 1000° C. (e.g., up to 1800° C.) and a pressure of up to about 800PSI (e.g., 300-800 PSI) in embodiments. For the diffusion bond betweenthe ceramic heater plate 310 and the additional ceramic heater plate315, an interface layer may be formed between the ceramic heater plate310 and the additional ceramic heater plate 315. The interface layer maybe composed of Y, Zr, Al and O.

The ceramic heater 310 may be exposed to a fluorine-based plasma at ahigh temperature (e.g., up to about 650° C.). Fluorine may form on asurface of the ceramic heater 310 and react with any trace metals suchas Al in the ceramic heater 310 (e.g., to form AlF₃). AlF₃ has a lowvapor pressure, and may thus vaporize or sublime at the temperatures ofup to about 650° C. The AlF₃ may then condense on other chambercomponents in the chamber, leading to particle contamination ofprocessed substrates. Accordingly, a ceramic material of Y₂O₃—ZrO₂ thatis very pure and that lacks Al or trace metals is used in embodiments toprevent fluoride buildup on chamber components. Since the ceramic heater310 supports substrates (similarly to the electrostatic chuck 148), thecomposition for the ceramic material of Y₂O₃—ZrO₂ with 55-65 mol % Y₂O₃and 35-45 mol % ZrO₂ is optimal or near optimal as it provides thehighest hardness, flexural strength and fracture toughness and highplasma erosion resistance.

FIGS. 4A-B illustrate a top view and bottom view of a process kit ring405, respectively, in accordance with embodiments. The process kit ring405 may correspond to ring 134 in embodiments. The process kit ring 405may have a thickness of about 0.5-1.5 inches, an inner diameter (ID)dimension of about 11-15 inches (e.g., about 11.8-14 inches) and anouter diameter (OD) dimension of about 12-16 inches in embodiments. Anouter edge of the top of the process kit ring 405 may be rounded inembodiments. The width of the ring (difference between ID and OD) may beabout 1-2.5 inches in embodiments. The process kit ring 405 may contacta supported substrate, and so may be subject to wear by such contact.Additionally, the process kit ring 405 has a relatively large diameterand is relatively thin and has a relatively small width. These factorsmay subject the process kit ring 405 to breakage during handling and/oruse. Moreover, the process kit ring 405 may be exposed to plasma duringprocessing. Accordingly, the process kit ring 405 benefits from thecombination of plasma resistance, hardness, flexural strength andfracture toughness exhibited by the ceramic material of Y₂O₃—ZrO₂ with55-65 mol % Y₂O₃ and 35-45 mol % ZrO₂ (e.g., ceramic materials ofY₂O₃—ZrO₂ that include about 60 mol % Y₂O₃ and about 40 mol % ZrO₂).

FIGS. 5A-B illustrate a top view and bottom view of a lid 505 for aprocessing chamber, respectively, in accordance with embodiments. Thelid 505 may correspond to lid 132 in embodiments. The lid 505 may have athickness of about 1-2 inches and a diameter of about 19-23 inches inembodiments. The lid 505 may contact other chamber components that mayhave a different coefficient of thermal expansion, and so may be subjectto wear by such contact. Additionally, the lid 505 has a relativelylarge diameter and is relatively thin. These factors may subject the lid505 to breakage during handling and/or use. Moreover, the lid 505 may beexposed to plasma during processing. Accordingly, the lid 505 benefitsfrom the combination of plasma resistance, hardness, flexural strengthand fracture toughness exhibited by the ceramic material of Y₂O₃—ZrO₂with 55-65 mol % Y₂O₃ and 35-45 mol % ZrO₂ (e.g., ceramic materials ofY₂O₃—ZrO₂ that include about 60 mol % Y₂O₃ and about 40 mol % ZrO₂).

FIGS. 6A-B illustrate a top view and bottom view of a nozzle 605 for aprocessing chamber, respectively, in accordance with embodiments. Thenozzle 605 may correspond to nozzle 152 in embodiments. The nozzle 605may include multiple gas delivery holes. The nozzle 605 may fit into ahole at or near a center of the lid 505.

In some embodiments a chamber may include a gas delivery plate (GDP)rather than a lid and nozzle. FIGS. 7A-B illustrate a top view andbottom view of a GDP 705 for a processing chamber, respectively, inaccordance with embodiments. The GDP 705 may include a large number(e.g., thousands) of gas delivery holes. The GDP 705 may have athickness of about 1 mm (e.g., 0.04) to about 1 inch and a diameter ofabout 18-22 inches in embodiments. In one embodiment, the GDP 705 has athickness of about 1-6 mm. The GDP 705 may be a load bearing component,and may have a relatively large diameter and be relatively thin. Thesefactors may subject the GDP 705 to breakage during handling and/or use.Moreover, the GDP 705 may be exposed to plasma during processing.Accordingly, the GDP 705 benefits from the combination of plasmaresistance, hardness, flexural strength and fracture toughness exhibitedby the ceramic material of Y₂O₃—ZrO₂ with 55-65 mol % Y₂O₃ and 35-45 mol% ZrO₂ (e.g., ceramic materials of Y₂O₃—ZrO₂ that include about 60 mol %Y₂O₃ and about 40 mol % ZrO₂). The beneficial dielectric breakdownresistance of the ceramic material of Y₂O₃—ZrO₂ with 55-65 mol % Y₂O₃and 35-45 mol % ZrO₂ (e.g., ceramic materials of Y₂O₃—ZrO₂ that includeabout 60 mol % Y₂O₃ and about 40 mol % ZrO₂) may also reduce arcing whenused for the GDP 705. In some embodiments, the GDP 705 is connected to abacking plate (e.g., a metal backing plate such as an Al backing plate)for added mechanical strength. The GDP 705 may be mechanically clampedto the backing plate or bonded to the backing plate (e.g., by adiffusion bond).

FIG. 8 is a flow chart showing a process 800 for manufacturing a solidsintered ceramic article, in accordance with one embodiment of thepresent disclosure. At block 855, ceramic powders of Y₂O₃ and ZrO₂ thatare to be used to form the ceramic article are selected. Quantities ofthe selected ceramic powders are also selected. The ceramic powder ofY₂O₃ may have a purity of at least 99.99% and the ceramic powder of ZrO₂may have a purity of at least 99.8% in embodiments.

At block 858, a purification process may be performed on the selectedpowders.

At block 860, the selected ceramic powders are mixed. In one embodiment,the selected ceramic powders are mixed with water, a binder and adeflocculant to form a slurry. In one embodiment, the ceramic powdersare mixed using a milling process, such as ball milling. The mixing maycause the ceramic particles to agglomerate into agglomerates having atarget particle size and a target size distribution. Notably, themixture of ceramic powders does not include any added sintering agentsin embodiments. In one embodiment, the ceramic powders are combined intoa granular powder by spray drying. The spray drying process may volatizea liquid or solvent in the agglomerates.

At block 865, a green body (an unsintered ceramic article) is formedfrom the mixed powders (e.g., from the slurry formed from a mixture ofthe selected ceramic powders). The green body can be formed usingtechniques including, but not limited to, slip casting, tape casting,cold isostatic pressing, unidirectional mechanical pressing, injectionmolding, and extrusion. For example, the slurry may be spray dried,placed into a mold, and pressed to form the green body in oneembodiment. In one embodiment, the green body is formed by coldisostatic pressing. The green body may have an approximate shape of achamber component to be manufactured.

In one embodiment, at block 866 green machining may be performed on thegreen body. The green machining may include, for example, drilling holesin the green body.

At block 868, a first heat treatment is performed on the green body toburn off an organic binder in the green body. In one embodiment, thefirst heat treatment is performed by exposing the green body to anelevated heat of about 950° C. for a duration of about 1-2 weeks.

At block 870, a second heat treatment is performed on the green body tosinter the green body and produce a sintered ceramic body consistingessentially of 55-65 mol % Y₂O₃ and 35-45 mol % ZrO₂, (e.g., consistingessentially of about 60 mol % Y₂O₃ and about 40 mol % ZrO₂). Sinteringthe green body may include heating the green body to a high temperaturethat is below the melting point of Y₂O₃ and ZrO₂. The second heattreatment process may be performed at a temperature of about 1750-1900°C. for a duration of about 3-30 hours in embodiments. In embodiments,the sintering may be performed in the presence of air, oxygen and/orhydrogen (e.g., by flowing any of these gases into a furnace that isheating the green body). The sintering process densifies the green bodyand produces a solid sintered ceramic article having a porosity of about0.1% that includes at least one Y₂O₃—ZrO₂ phase (e.g., a Y₂O₃—ZrO₂ solidsolution). The sintering process may be a pressureless sintering processin embodiments.

In various embodiments, the solid sintered ceramic article may be usedfor different chamber components of a plasma etch reactor or otherchamber. Depending on the particular chamber component that is beingproduced, the green body may have different shapes. For example, if theultimate chamber component is to be a process kit ring, then the greenbody may be in the shape of a ring. If the chamber component is to be anelectrostatic puck for an electrostatic chuck, then the green body maybe in the shape of a disc. The green body may also have other shapesdepending on the chamber component that is to be produced.

The sintering process typically changes the size of the ceramic articleby an uncontrolled amount. Due at least in part to this change in size,the ceramic article is typically machined after the sintering process iscompleted at block 875. The machining may include surface grindingand/or polishing the ceramic article, drilling holes in the ceramicarticle, cutting and/or shaping the ceramic article, grinding theceramic article, polishing the ceramic article (e.g., using chemicalmechanical planarization (CMP), flame polishing, or other polishingtechniques), roughening the ceramic article (e.g., by bead blasting),forming mesas on the ceramic article, and so forth.

After sintering, the sintered ceramic body may have colornon-uniformities. The color non-uniformities may be defects that causechamber components formed from the sintered ceramic body to be returnedby customers. Accordingly, in one embodiment at block 880 a third heattreatment is performed on the sintered ceramic body to homogenize acolor of the sintered ceramic body. In embodiments, the sintered ceramicbody has a uniform white color after the third heat treatment. The thirdheat treatment may be performed at a temperature of about 1000-1400° C.for a duration of 2-12 hours.

In one embodiment, the machining processes of blocks 866 and/or 875 arerough machining processes that cause the sintered ceramic body toroughly have a target shape and features. In one embodiment, at block885 the solid sintered ceramic body is again machined using anadditional machining process. The additional machining process may be afine machining process that causes the sintered ceramic body to have atarget shape, roughness and/or features. The ceramic article may bemachined into a configuration that is appropriate for a particularapplication. Prior to machining, the ceramic article may have a roughshape and size appropriate for a particular purpose (e.g., to be used asa lid in a plasma etcher). However, the machining may be performed toprecisely control size, shape, dimensions, hole sizes, and so forth ofthe chamber component.

The machining processes of blocks 866, 875 and/or 885 may introducetrace metal impurities to the sintered ceramic article. Additionally,the sintered ceramic article may include a very low amount of tracemetal impurities introduced by the original ceramic powders and/or othermanufacturing steps. For chamber components that will be exposed tofluorine based plasmas, even a very small amount of metal impurities maybe detrimental to processed substrates. Accordingly, at block 890 afinal purification process may be performed on the sintered ceramicbody. After purification, metal contaminants may be removed such thatthere are no metal contaminants with a value of 100 parts per million(ppm) or higher in the ceramic body. Accordingly, an overall purity ofthe ceramic body after the purification process may be 99.9%. In oneembodiment, the final purification process includes a wet clean processand/or a dry clean process. The final purification process may removetrace metal contaminants from a surface of the sintered ceramic body inembodiments. In other embodiments, the final purification process mayremove trace metal contaminants from the inside of the ceramic body aswell as a surface of the ceramic body.

Table 2 below provides metal impurities for ceramic bodies manufacturedin accordance with method 800. The metal impurities were measured byGDMS analysis and are expressed in terms of parts per million (ppm) byweight (wt.).

TABLE 2 Metal Impurities Metal Impurity Al ≤30 B ≤20 Ca ≤50 Cr ≤10 Co≤10 Cu ≤10 Fe ≤50 Pb ≤20 Li ≤20 Mg ≤20 Mn ≤10 Ni ≤10 K ≤10 Na ≤50 Sn ≤50Zn ≤20

Depending on the particular chamber component that is to be produced,additional processing operations may additionally be performed. In oneembodiment, the additional processing operations include bonding thesolid sintered ceramic body to a metal body or other body (block 895).In some instances, in which the solid sintered ceramic body is bothmachined and bonded to a metal body, the machining may be performedfirst, followed by the bonding. In other instances, the solid sinteredceramic article may first be bonded to a metal body, and may then bemachined. In other embodiments, some machining is performed both beforeand after the bonding. Additionally, in some embodiments the solidsintered ceramic article may be bonded to another ceramic article.

In a first example, the ceramic article is to be used for a showerheador GDP. In such an embodiment, many holes may be drilled into theceramic article, and the ceramic article may be bonded to an aluminumgas distribution plate. In a second example, the ceramic article is usedfor an electrostatic chuck. In such an embodiment, helium pin holes aredrilled into the ceramic article (e.g., by laser drilling), and theceramic article may be bonded by a silicone bond or diffusion bond to analuminum base plate. In another example, the ceramic article is aceramic lid. Since the ceramic lid has a large surface area, the ceramiclid formed from the new sintered ceramic material may have a highstructural strength to prevent cracking or buckling during processing(e.g., when a vacuum is applied to a process chamber of the plasma etchreactor). In other examples, a nozzle, a process kit ring, or otherchamber component is formed.

The preceding description sets forth numerous specific details such asexamples of specific systems, components, methods, and so forth, inorder to provide a good understanding of several embodiments of thepresent disclosure. It will be apparent to one skilled in the art,however, that at least some embodiments of the present disclosure may bepracticed without these specific details. In other instances, well-knowncomponents or methods are not described in detail or are presented insimple block diagram format in order to avoid unnecessarily obscuringthe present disclosure. Thus, the specific details set forth are merelyexemplary. Particular implementations may vary from these exemplarydetails and still be contemplated to be within the scope of the presentdisclosure.

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure, orcharacteristic described in connection with the embodiment is includedin at least one embodiment. Thus, the appearances of the phrase “in oneembodiment” or “in an embodiment” in various places throughout thisspecification are not necessarily all referring to the same embodiment.In addition, the term “or” is intended to mean an inclusive “or” ratherthan an exclusive “or.”

Although the operations of the methods herein are shown and described ina particular order, the order of the operations of each method may bealtered so that certain operations may be performed in an inverse orderor so that certain operation may be performed, at least in part,concurrently with other operations. In another embodiment, instructionsor sub-operations of distinct operations may be in an intermittentand/or alternating manner.

It is to be understood that the above description is intended to beillustrative, and not restrictive. Many other embodiments will beapparent to those of skill in the art upon reading and understanding theabove description. The scope of the disclosure should, therefore, bedetermined with reference to the appended claims, along with the fullscope of equivalents to which such claims are entitled.

What is claimed is:
 1. A method of manufacturing a chamber component fora processing chamber, comprising: mixing a Y₂O₃ powder with a ZrO₂powder to form a Y₂O₃-ZrO₂ powder consisting essentially of 55-65 mol %Y₂O₃ and 35-45 mol % ZrO₂; performing cold isostatic pressing using theY₂O₃-ZrO₂ powder to form a green body having an approximate shape of thechamber component; performing a first heat treatment on the green bodyto burn off an organic binder in the green body; subsequently performinga second heat treatment on the green body at a temperature of about1750-1900° C. to sinter the green body and produce a sintered ceramicbody consisting essentially of one or more phase of Y₂O₃-ZrO₂, thesintered ceramic body consisting essentially of 55-65 mol % Y₂O₃ and35-45 mol % ZrO₂; machining the sintered ceramic body; and performing apurification process on the sintered ceramic body to remove trace metalsfrom the sintered ceramic body, wherein after the purification processthe sintered ceramic body has a purity of at least 99.9%.
 2. The methodof claim 1, further comprising: performing a third heat treatment on thesintered ceramic body after performing the machining of the sinteredceramic body, wherein the third heat treatment is performed at atemperature of about 1000-1400° C. and homogenizes a color of thesintered ceramic body.
 3. The method of claim 2, further comprising:performing an additional machining process on the sintered ceramic bodyafter performing the third heat treatment and prior to performing thepurification process.
 4. The method of claim 1, wherein the sinteredceramic body consists essentially of 59-61 mol % Y₂O₃ and 39-41 mol %ZrO₂.
 5. The method of claim 1, wherein the Y₂O₃ powder has a purity ofat least 99.99% and the ZrO₂ powder has a purity of at least 99.8%. 6.The method of claim 1, wherein the sintered ceramic body consistsessentially of 57-63 mol % Y₂O₃ and 37-43 mol % ZrO₂.
 7. The method ofclaim 1, wherein the sintered ceramic body consists essentially of 58-62mol % Y₂O₃ and 38-42 mol % ZrO₂.
 8. The method of claim 1, wherein thechamber component is a nozzle that consists of the sintered ceramicbody, the nozzle comprising a plurality of through gas delivery holes.9. The method of claim 1, wherein the chamber component is a curved doorto the processing chamber, the sintered ceramic body having a thicknessof about 0.5-1.5 inches, a length of about 3-6 inches and a height ofabout 10-14 inches.
 10. The method of claim 1, wherein the chambercomponent is a lid consisting of the sintered ceramic body, the sinteredceramic body having a thickness of about 1-2 inches and a diameter ofabout 19-23 inches.
 11. The method of claim 1, wherein the chambercomponent is an electrostatic chuck, and wherein the sintered ceramicbody is a puck for the electrostatic chuck, the method furthercomprising: bonding a thermally conductive base to a lower surface ofthe sintered ceramic body, the thermally conductive base consistingessentially of Al, wherein a side wall of the thermally conductive basecomprises an anodization layer of Al₂O₃.
 12. The method of claim 1,wherein the chamber component is a heater configured to support and heata wafer, wherein the sintered ceramic body is a flat ceramic heaterplate, the method further comprising: bonding a funnel shaped shaft tothe flat ceramic heater plate.
 13. The method of claim 1, wherein thesintered ceramic body has a Vicker Hardness of about 9.1-9.4 GPa. 14.The method of claim 1, wherein the sintered ceramic body has a thermalexpansion coefficient of about 9.4-9.6.
 15. The method of claim 1,wherein the sintered ceramic body has a dielectric breakdown resistanceof about 500-600 V/mil.
 16. The method of claim 1, wherein the sinteredceramic body has an average flexural strength of about 139.4-150 MPa.17. A method of manufacturing a chamber component for a processingchamber, comprising: forming a green body using a Y₂O₃—ZrO₂ powderconsisting essentially of 55-65 mol % Y₂O₃ and 35-45 mol % ZrO₂; andsintering the green body to produce a sintered ceramic body consistingessentially of one or more phase of Y₂O₃—ZrO₂, the sintered ceramic bodyconsisting essentially of 55-65 mol % Y₂O₃ and 35-45 mol % ZrO₂, whereinthe sintered ceramic body has a purity of over 99.9%.
 18. The method ofclaim 17, further comprising: machining the sintered ceramic body; andperforming a purification process on the sintered ceramic body to removetrace metals from the sintered ceramic body, wherein after thepurification process the sintered ceramic body has the purity of over99.9%.
 19. The method of claim 17, wherein: forming the green bodycomprises: mixing a Y₂O₃ powder with a ZrO₂ powder to form the Y₂O₃—ZrO₂powder consisting essentially of 55-65 mol % Y₂O₃ and 35-45 mol % ZrO₂;and performing cold isostatic pressing using the Y₂O₃—ZrO₂ powder toform the green body, the green body having an approximate shape of thechamber component; the method further comprises performing a first heattreatment on the green body to burn off an organic binder in the greenbody prior to the sintering; and the sintering comprises performing asecond heat treatment on the green body at a temperature of about1750-1900° C.